Initial development of FreeBSD was started in November of 1993 by Jordan Hubbard, and took its sources from 386BSD. However, due to concerns about the legality of all the sources used in 386BSD, FreeBSD re-engineered much of the system with the FreeBSD 2.0 release in January of 1995 using the 4.4BSD-Lite release from the University of California, Berkeley (and, again, at FreeBSD 3.0, that time from the 4.4BSD-Lite2 release). The current (June 2003) FreeBSD release is FreeBSD 5.1.
The latest stable version of FreeBSD is 4.8, but work on the version 5-branch is constantly being made.

FreeBSD is released under the BSD License, which allows everyone to use and redistribute FreeBSD as they wish, as long as they do not remove the copyright notice and the BSD license itself (which does not prohibit re-licensing).

A version based on the GNU toolset is currently being developped by Debian as Debian GNU/FreeBSD.